The Problem with Finding Out from Users
There's a particular kind of dread that comes with opening Slack and seeing "Hey, is the site down?" from a customer. By the time a user notices and reports an outage, it's already been down for minutes — sometimes much longer. Uptime monitoring exists to flip this dynamic: you find out first, before a single complaint comes in.
This guide explains how uptime monitoring works, what to track, and how to set it up properly.
How Uptime Monitoring Works
An uptime monitor is a service that regularly sends HTTP requests to your application's endpoints from external locations. If a request fails — due to a timeout, a connection error, or a non-2xx response — the monitor triggers an alert.
The key word is *external*. Monitoring from within your own infrastructure can miss networking issues, DNS failures, and problems that only appear at the edge. A good uptime check simulates what a real user experiences when they try to reach your site.
Typical check intervals range from 30 seconds to 5 minutes depending on how critical the service is and how fast you need to know.
What to Monitor
Your Primary Domain
The most obvious check: make sure your main URL returns 200. This catches web server crashes, SSL certificate expiration, and DNS misconfigurations.
Health Check Endpoints
Many applications expose a /health or /status endpoint that tests internal dependencies — database connections, cache availability, third-party APIs. Monitoring this endpoint catches more than a surface-level HTTP check.
API Endpoints
If your application serves an API, monitor your most critical endpoints individually. A failing auth endpoint or a broken payments route can hurt your business even if the homepage looks fine.
Static Assets
For static sites deployed on CDNs, monitor that your key assets (the main HTML file, your JS bundle) are being served correctly and haven't been accidentally invalidated.
Uptime Monitoring on PandaStack
PandaStack includes built-in uptime monitoring for all deployment types: static sites, Docker containers, databases (PostgreSQL, MySQL, Redis, MongoDB), cronjobs, and edge functions running on Node.js or Python via OpenWhisk.
You don't need to sign up for a separate monitoring service. From [dashboard.pandastack.io](https://dashboard.pandastack.io), you can enable uptime checks on any deployed resource and configure alerts directly in the same interface.
Setting Up Alerts
Once you enable uptime monitoring, configure at least one notification channel:
- Email — Good for non-critical services or out-of-hours alerting
- Slack — Best for team-facing alerts where you need fast acknowledgement
- Webhook — For integrating with incident management systems or custom tooling
PandaStack supports all three, so your alert goes to wherever your team is most likely to respond quickly.
Understanding Uptime SLAs
If you're offering any kind of service-level agreement to customers, uptime monitoring gives you the data to back it up. Common SLA targets:
| SLA | Max downtime per month |
|---|---|
| 99% | ~7.3 hours |
| 99.9% | ~43.8 minutes |
| 99.95% | ~21.9 minutes |
| 99.99% | ~4.4 minutes |
Hitting 99.9% is achievable for most applications with good infrastructure and fast incident response. Hitting 99.99% requires redundancy and near-instant alerting.
Common Causes of Downtime
Knowing what to watch for helps you respond faster:
- Deploys gone wrong — A bad release that crashes on startup
- Database connection exhaustion — Too many connections, app can't serve requests
- Memory leaks — Container gets OOM-killed after days of running
- Certificate expiry — HTTPS stops working because nobody renewed the cert
- Dependency failures — A third-party API your app depends on goes down
Uptime monitoring doesn't prevent these, but it ensures you know about them in seconds rather than hours.
Reducing Alert Fatigue
Not every blip deserves a wake-up call. Configure your uptime monitor to require consecutive failures before alerting (e.g., "alert after 2 failed checks in a row"). This filters out transient network hiccups without leaving real outages undetected.
Conclusion
Uptime monitoring is the most fundamental layer of application observability. It's the difference between proactive incident response and reactive damage control. PandaStack makes it easy — deploy your application, enable monitoring from [dashboard.pandastack.io](https://dashboard.pandastack.io), and configure your alert channels. You'll be the first to know when something goes wrong, not the last.